Traditional Fish Rocker-- Help me get it right this time...

General Discussion
1

Hey Guys.

I recently shaped my first board. It’s a 5’10" X 21.25 X 3 retro twin keel fish. The problem is, I really botched the rocker. I knew that a fish needed minimal rocker, but I made a mistake right from the beginning. I was stuck with a 6’10" fish blank (US Blank, I believe) and I took most of the length from the tail, trying to be sure that I would have enough rocker in the nose… In hindsight, that was a dumb idea… I have nearly 5 inches of nose rocker, and I have 2 inches of tail rocker… And this nose rocker isn’t just a flip in the nose, its pretty well distributed through the front half of the board. I definitely learned a lot with this first shape, and I am really amped to take another stab at it.

So I’m going to try another fish in a couple weeks here, and see if I can learn from my mistakes. I am going to stick with the 5’10" length, go with a 21" width, and drop the thickness to about 2 5/8 inches. So what do you think would be some good rocker numbers for this board? I have read many posts which mention numbers something like 3.5 inch nose rocker, and 1.5 or so inches of tail rocker. But how is this rocker distributed? Could anyone help me out with some rocker numbers at, say, one foot from nose and tail? I just want to get it right this time…

I was just taking a look at the pdf thats been floating around the boards here of the Steve Lis 5’5" fish. The little section on rocker has me a little bit confused… I was trying to recreate this rocker in Aku Shaper just to get a visual of it, and it just isn’t panning out. The 3 1/4 of rocker at the nose makes sense, but the 3" at 63" (which is 5’3") seems like a bit much. I just can’t get a nice looking curve with 3.25 inches at the nose, and loosing only 0.25 inches of rocker in the first 2 inches of the board. If I make it about 2.6 inches of rocker at 5’3", it looks much more natural to me. Also, if I am interpreting this correctly, the rear 3 feet of the board has zero rocker. Wouldn’t this mean that the rear 3 feet of the board are completely flat and the tangent at the midpoint is parallel to this flat, 3 foot section?

Sorry about the rambling post with lots of questions, but I’m really just looking for any insight into the subject. So thank you all in advance for any thoughts. Hopefully with your help I can create a killer fish my second go-around.

2

I think this looks nice…

3

That does look nice. That looks really similar to the rocker I just worked up a few minutes ago. Not sure how the numbers match up, but it sure looks close.

4

Also, go to Harbour Surfboards and check out his fish. He has a rocker shot when you click on it.

5

That harbour looks like it has VERY little rocker… It looks like it has almost the same rocker in the nose and tail. Of course thats just by holding a piece of paper up to my computer screen where it looks tangent… It almost looks like the bottom follows one single, wide, circular arc. That definitely looks different to me than what you and I came up with, where the rocker is more concentrated toward the nose of the board in a progressive manner.

6

yeah, but it’s good to see alot of different types so to better make a decision as to what you want to make yourself. I would think that Harbours is more “traditional” with its minimum rocker.

As you can see here that the picture i drew is a thinned out tracing of the CI fish which would be a more hi performance fish.

7

Definitely good to see all the different designs. If nothing else, it confirms that no matter what i end up with, it will most likely ride just fine. Even that first one I shaped is still fun to ride on small days. It definitely pushes water while I’m paddling, and isn’t quite as fast as I would have liked, but it is really loose, and fun to swish around on when its less than chest high, and gutless.

So do you think I could end up with a good rocker if I started with the 6’2" A from US Blanks, and positioned my 5’10" toward the tail of the blank? It sounds like this is what some other folks on the board here have done.

8

Fish rocker can be subject to a lot of variables, and of course all this is just IMO, but here goes:

The big beefy fishes with hard down rails and flat bottoms need more rocker.

Thinner, round rail fishes with roll and/or V bottoms should be much flatter rocker.

Most of the ‘‘stock’’ rockered PU blanks have way too much rocker, almost all the good fish shapers

had custom rockers on the Clark 6’2’'C that were much flatter than the ‘‘natural’’.

Flipping the tip on a fish is a waste of time and paddling effort, just make the thing short enough

that the nose is out of the way.

I’m not going to hand out #'s because I think everyone should figure it out for themselves. Find what

works best for you.

Mike

9

…I can add that the Rhyno 6Kfish, has too much nose rocker if you do a concave bottom

and no margin of error if you do a 5 10 x 2 5/8 or almost 2 3/4 for ex

and the 6 2 F from Surfblanks/Teccel has too much overall rocker but better dims and more room

also you can do a flat or domedeck and keep the thickness thick (more beefy)

10
Quote:

Fish rocker can be subject to a lot of variables, and of course all this is just IMO, but here goes:

The big beefy fishes with hard down rails and flat bottoms need more rocker.

Thinner, round rail fishes with roll and/or V bottoms should be much flatter rocker.

Most of the ‘‘stock’’ rockered PU blanks have way too much rocker, almost all the good fish shapers

had custom rockers on the Clark 6’2’'C that were much flatter than the ‘‘natural’’.

Flipping the tip on a fish is a waste of time and paddling effort, just make the thing short enough

that the nose is out of the way.

I’m not going to hand out #'s because I think everyone should figure it out for themselves. Find what

works best for you.

Mike

Ah, but what are YOU riding? You must describe very thoroughly and provide copious pictures now…

; )

g

11 
I definitely understand your thoughts about finding my own numbers. Thats what makes shaping interesting to me, just that you can do whatever you want. Even if it doesn't come out just as I plan, I'm sure it will work great in some set of conditions. 



I don't mean to be asking for you all to design a board for me, more just to throw out some numbers that have worked for other people so that I have a basis to work from. After shaping just one board, I am fully hooked on shaping. I think about it way to much... I plan to shape many more boards, and try many different designs. The problem is (I guess it really isn't a problem, per se...) right now I'm a grad student with very little fundage to throw into my hobbies... So for now, I just want to shape something that will perform for me. I'll have lots of time (and more money) to play around with in the future. 



Anyway.... US Blanks offers a 6'2"A blank with a rocker of -3/8" from the nose (compared to the natural rocker). Do you suppose this would be a better starting point than the natural rocker? 



I guess I am just trying to avoid the problem I had last time... I couldn't figure out a way to thin out the nose and tail without coming up from the bottom, and increasing the rocker to much (which is what I ended up doing) or shaving more foam off the deck. I have always been told that you want to leave as much as possible on the deck after it's skinned. I guess either way starting with the right blank will help me avoid this problem.
12

805- This might help, posted by Plus one shaper a while back.

I posted some numbers way back and also corresponded by PM with quite a few shapers about rocker

numbers. I have re-submitted the numbers here, sorry if it runs a bit long, but the explanation is quite

important to get the rocker just right…

True Classic 5’6" fish

N: 3-5/16

12: 11/16

24: 1/16

C: 0

24: 1/8+

12: 1/2+

T: 1-1/16- (where ‘+’ and ‘-’ are about 1/32")

Performance 5’6" fish

N: 3-13/16

12: 1

24: 3/16-

C: 0

24: 3/16

12: 5/8

T: 1-5/16-

Start with a horizontal line, find the halfway point, C, and spec the points: N and T are obvious. 12 means 12 inches from the nose or tail, and likewise for 24.

Best to use a long flexible stick, (spline) with good continuous wood grain. Floor molding strips work well, (those quarter round little wood strips that have no knots or wierd grain). Some use fishing pole blanks. I’ve used masking tape before but that took about 10 years to get my skills up. Better find a stick… …put weights on it. Do the front half separately from the rear.

The above numbers may seem a bit flat but this is what works for this length (I can suggest numbers for a longer fish). Rocker might get altered for thicker boards but most boards run about 2-1/4 thick to 2-3/8. I’m 170 lbs, and I have a couple 5’8" x 19-3/4 x 2-1/4 performance models that work quite well. I have a 5’7" that is great in bigger waves, it has the Vee hull. Most of these things have flat decks BUT pinched rails with very little vertical “sidewalls” especially at the water entry- kinda knifey.

…my suggestion is to start by making a 5’6" rocker template (female version, so it can fit to your boards) and then

decide how you want to scoot your 5’4" around. One bit of advice for true twin keels, they really do not benefit from any tail kick at all or flat-to-vee in the tail, they will just bog. You almost want to lay a straight edge along the last 20" of tail!

Bottom contour can run 3 ways and work quite well. Stevie/Stanley made them Flat-to-flat, and Slight belly-to-flat. Duff started with Flat-to-flat and later made some with concave-to-flat. Belik is all about concaves and started trenching a tunnel down the middle of his boards. I’ve met a lot of success with subtle concave (1/8") just ahead of the front foot and dead flat in the last 1/3 of the board.

Edges. Pavel used to joke: “it all works, everything works, that’s the problem”. I’ve seen sharp edge from nose to tail like Bunker and Mansfield rode, and they worked. I’ve seen Pendo do hard 45deg bevels for tucked rails and it worked. Belik uses chines all the time. I’ve seen Geppy have normal rails up front and hard edges for the last 2 feet and it worked. I’ve been doing standard round rails and slight beveled rails that transition to a hard edge Mid-Keel and they work.

So I guess the moral of the story is “pick your poison” (lol). Actually, just go with your instincts, your first inclination tends to be the correct approach.

Anyways, sorry for crapping-on, hope this helps.

George (Plusone surfboards)

Jim

13

The minus 3/8’’ on the 6’2’’ A is going to be a better start than the natural, IMO. Fish foils and rockers

are all over the place, as you’re finding out, so there really aren’t any close tolerance blanks. You’re always

going to have to mow off a good deal of foam. Taking a lot off the deckside at the tips isn’t that bad, if the

foam has a density gradient you just want to make sure you don’t take too much off under your feet. I used

to plow off about an inch and a half on a 6’2’'C in the tail (even after custom rocker, just to get the thickness

down) and just live with the crushed deck.

The plusone post has some good #'s in it, and he notes that ‘‘it all works’’. What I ride might suck for you.

janklow knows I won’t post pics of my fish and just likes to torture me. My board is heavily influenced by a close

friend who doesn’t share our enthusiasm for internet forums, and I respect him too much to violate his trust.

And our fishes aren’t the easiest thing to ride anyway, they’re kinda like the hull boards in that they require

a certain commitment from the rider and they don’t forgive mistakes.

Enjoy the shaping, I still think about it way too much also, even after many, many years of doing it.

Mike

14

Thanks for all the great replies. I’ve learned a lot in the last day or two.

I just found out that the Fiberglass Hawaii shop that was in Santa Cruz combined with their shop in Ventura. I’m smack in between the two, in San Luis Obispo. Would the Ventura shop stock the -3/8" rocker in the 6’2" A, or for that matter, would they order it for me? I’d rather not have to deal with shipping a blank if I can avoid it… I guess I could just call them tomorrow when they are open, but I can’t stop thinking about it right now…

15

I do believe they will order whatever you want, surfer805. Give em a call. Looking forward to seeing the board. Mike

16

Hmm… I’m trying to attach some crappy phone pictures to this message… but it’s not working. The help section says that pictures must be less than 90 kb, and both are about 75 kb. Then when I try to attach them, it says that they exceed the maximum size of 34.2 kb… Thats REALLY small… I know for a fact that people are posting pictures bigger than that… Whats up with that?

17

Open an account with an online free image hosting site, like photobucket. Then you can just paste the code into the body of the post and it will appear as large as it is.

See…

Me and the Mrs

18

Lets try this again… I think I can just link to the pictures from my Verizon site where I sent them from my phone?

Here it goes… This is my first stab at shaping:

And here is a shot showing my botched rocker and foil (Kindof shaped like a banana when you look at it from the side… Haha): Sorry it’s sideways…

19

pix not showing

20

One more try… My first shape.

Here’s the board:

And a rocker shot: